The present invention relates to a card-equipped portable telephone set with excellent security which is set in a usable state when a user inputs a password, and allows easy management.
A card unit is added to a conventional card-equipped portable telephone set of this type to add various functions to a portable telephone set equipped with no card.
Japanese Patent Laid-Open No. 3-76364 discloses a technique of changing the function settings of the push keys by using various types of IC cards (a sales management card, a telephone directory card, individual customer cards, and the like) prepared in accordance with functions. According to this technique, a compact portable telephone set can be effectively used by using different IC cards in accordance with application purposes.
Japanese Patent Laid-Open No. 4-14916 discloses a portable telephone set which serves as a receive-only telephone set when no card is inserted, but allows an originating operation when a card is inserted. According to this portable telephone set, a destination telephone number is input through a ten-keypad prepared on the card, and the card in which the destination telephone number is input is inserted into the portable telephone set, thereby allowing an originating operation. Even if, therefore, the portable telephone set is lost or stolen, no originating call can be illegally generated unless the card is inserted in the telephone set.
As described above, a conventional card-equipped portable telephone set incorporates all the essential functions of the portable telephone set, and cards are used to add additional functions. That is, even if no card is inserted in the portable telephone set, since identification information and the like are stored in the main body of the telephone set, it can be used as a portable telephone set even though some restrictions are imposed thereon.
In addition, when, for example, a new portable telephone set is bought to replace the old one, the telephone number must be changed. This problem is common to portable telephone sets equipped with no cards. Furthermore, when a portable telephone set is lost, a finder can easily and illegally use it. As a result, the owner of the lost telephone set is charged. That is, a problem is posed in terms of security. Moreover, there is a shortage of physical circuit numbers on the portable telephone business side.